He said some companies were seeking to raise prices to counter
the falling pound's impact on their global revenue, indicating
such a move was not "justified."

"I spent 28 years working in a multinational and there are always
elements of currency volatility in businesses like
that," Lewis told reporters on Thursday at briefing at
Tesco's headquarters.

"When there is devaluation, what multinationals do is they
present sales at constant and current exchange rates," he said.

"And the City completely understands it, they don't devalue
a stock because of that, they understand it's part of the
volatility of being in many countries," Lewis said.

"The only thing we would ask is that companies in that position
don't ask UK customers to pay inflated prices in order that their
reporting currency is maintained. They don't do that to countries
outside of the UK."

The pound fell 18% against a trade-weighted index of currencies
after the vote to leave the European Union in June.

The move is already starting to have an impact in the UK, with
the prices of many household brands shooting up as the value of
the pound falls, and goods cost more to import.

The price increases sparked a dispute between Tesco and
Unilever, with the former threatening to take the latter's
brands off its shelves.

Lewis, who worked at Unilever for 28 years before joining Tesco
as CEO, added there was room for negotiation: "There's pressure.
Some of it is justified and if we can't offset it then we work
out how it is we can accommodate that between ourselves and
indeed our partners."

Higher prices and smaller food portions look set to become the
norm. Ben Broadbent, a deputy governor at the Bank of England
said there would ben“significant upward pressure on import
prices” in a speech on Friday.

Broadbent said the pound’s 11% plunge against
the dollar shortly after the June referendum was the
fastest depreciation since 1967.